The mill would employ 400 workers and would crank out 1.2 million tons of steel plate products annually, potentially competing with ArcelorMittal's plate operations in Burns Harbor and Gary.

ArcelorMittal employs more than 600 workers at Burns Harbor Plate and Gary Plate, who make steel plates of up to 160 inches for the construction, energy, heavy equipment, military, pipe and tube, rail car and shipbuilding industries. Plate made at Burns Harbor, for instance, is used in Navy submarines and other warships.

Charlotte-based Nucor, which already operates plate mills in North Carolina, Alabama and Texas, said the mill will make cut-to-length, coiled, heat-treated and discrete plate from 60 to 160 inches wide that it does not currently offer. The plate gauges will range from 3/16 of an inch to 14 inches in thickness.

"This investment is consistent with our drive to continue delivering sustainable, profitable growth and superior returns for shareholders," Nucor Chairman, CEO and President John Ferriola said. "Together with the significant share repurchases completed in 2018, the board's decision to fund this high-return opportunity demonstrates our commitment to balanced capital allocation."

Nucor has not yet identified where it will build the plate mill, which is expected to be up and running by 2022.

Nucor Executive Vice President of Beam and Plate Products Leon Topalian said the company expects to select a site for the new mill early this year.

"By building this state-of-the-art plate mill in the Midwest — the largest plate-consuming area in the United States — we will enhance our ability to serve our customers in the region while also furthering our goal of meeting all the steel needs of our customers around the country," he said.

Chuck Bradford, a New York City-based steel industry analyst with Bradford Research, said Nucor reportedly has eyed sites in Indiana, Ohio and West Virginia. Nucor already operates a mini mill in Crawfordsville.

Bradford said it was unlikely the company would look at locations in Northwest Indiana because it does not like to work with unions.

"They don't want even the hint of a union," he said.

Nucor wants to build a new mill at a time when the U.S. steel industry is only operating at about 80 percent of capacity.

"Frankly, I am really concerned about overcapacity," Bradford said. "But not all of the extra capacity is the most efficient capacity in the world."

Plate prices have remained relatively stable, especially as compared to other steel projects, largely because of a high degree of consolidation that's followed the closing of old plate mills like City Steel in Delaware.

"There are only a few producers, so there's not a lot of price volatility," Bradford said. "Nucor is known for taking chances. With new technology, they may think they're able to make products that are now imported."